276 SUMMARY OF GUEKEIST RESEARCHES RELATING TO 



plasts. Finally, comparison with Ulothrix crenulata (Kiitz.) Brand showed 

 that the two were identical. Tubeuf adds a note of warning against 

 confusing the above-described algal growth with the greyish-white 

 covering of a lichen on the pure black of the fungus Apiosporinm 

 pinophilum. E. S. G. 



Retention of Vitality by Algae from old Stored Soils. — B.Muriel 

 Bristol {New Phytologist, 18, 1918, 92-107, figs.). By culture of 

 old stored soils from Rothampstead it was found that some of the 

 Myxophyceai, Bacillariese, and Chlorophycea; have extraordinary powers 

 of retaining vitality during long periods of rest, and that the length of 

 time after which they can resume growth appears to be affected by the 

 degree of dryness of the soil during the resting period. The greatest 

 power of resistance against desiccation was shown by Nostoc muscorum 

 and Nodular id Harveyana, which resumed growth after extreme desicca- 

 tion for 70 years ; others— iVos^oc Passer inianum, Anahsena oscillarioides 

 var. terrestris, Cylindrospermum Uchiniforme, Chlorococcum humicola 

 — after 59 years ; Trochiscia aspera, Stichococcus hacMlaris, Nitzschia 

 Paha, after 48 years ; Plecionema Battersii, Rapnlosiphon Jfexuosus, 

 Phormidium tenue, after 47 years ; and Anabsena laxa after 48 years. 

 Though the algte described from the cultures differ somewhat from 

 typical forms, yet they are probably only cultural variants. A. G. 



Malay Form of Chlorococcum humicola (Nag.) Rabenh. — B. 

 Muriel Bristol {Journ. Linn. Soc, BoL, 1919, 44, 473-82, 2 pis.). 

 An account of an alga obtained by culture from a sample of soil from 

 Kuala Lumpur, which had been dried and stored in a closed tube for 

 two years. The vegetative cells and their contents are described. Adult 

 cells are coenocytic, with many pyrenoids. Propagation is effected by 

 biciliate zoogonidia, which are asexual or may act as gametes. Aplano- 

 sporea also may be formed, and enter into a palmelloid state, eventually 

 turning into zoogonidia or developing directly into vegetative cells. 

 Chlorococcus humicola occurs almost universally in English soils, and its 

 retention of vitality in long-dried soils has been found to exceed seventy 

 years. A. G. 



Contribution to the Algal Flora of South Luxembourg. — H. 

 KuFFERATH (Bull. Soc. R. Bot Belg., 1914, 53, 88-110). An account 

 of a collection of Desmids from the environs of Virton and from 

 Stockeen, a region hitherto unexplored algologically. Jurassic lime- 

 stone is found there. The area belongs geologically to the Paris basin 

 and to non-calcareous regions. The algal flora resembles partly the 

 Ardennes flora and partly that of Lorraine. The climate is mild, and 

 the soil varies from the hardest limestone to windswept sand. Eighty- 

 one species and varieties are recorded, of which forty-five are new to 

 Belgium and fifty-eight new to the province of Luxembourg. The author 

 makes a very strong appeal to algologists to divide up the areas they 

 study into natural regions, and not according to political limits ; to study 

 and publish more exact details as to nature of soil, formation of rock, 

 constituents of the water, and so on. He would also have the exact 

 locality given, according to the official ordnance maps, with indications 



